Interesting question
Usually when you look at something like that construction, you think that AB has been bisected by PQ and that the two segments are perpendicular. They are perpendicular but nowhere is that stated. So the answer is C because all the other answers are wrong.
PQ is congruent AB is not correct. As long as the arcs are equal and meet above and below AB there is no proof of congruency. In your mind widen the compass legs so that they are wider than AB and redraw the arcs. You get a larger PQ, but it has all the original properties of PQ except size.
PQ is not congruent to AQ. How would you prove conguency? You'd have to put both lines into triangles that can be proved congruent. It can't be done.
The two lines are not parallel. They are perpendicular. That can be proven. They meet at right angles to each other (also provable).
So, the sphere went from 1.2 meters to 1.4 meters.
The radius will always be half of the diameter. So it went from .6 to .7.
Let's divide and see what percent .7 is of .6.
.7÷.6=1.166666666(repeating 6).
This means, it increased by about 16.7%, since it was not doubling, just going up.
Assuming you are talking about the rectangle,
width = area/lenght
For numbers 15-17, we need to remember that two of a triangle's angles are always acute and the third angle will allow us to classify the triangle based on its angles. now that we know this, let's look at #15. the first two angles listed are acute, and the third is an obtuse angle, therefore it is an obtuse triangle. on #16 we have three acute angles, so it is an acute triangle. #17 has two acute angles and a right angle so it is a right triangle.
on numbers 21-23, we need to know that a triangle with all congruent sides is called equilateral, a triangle with two equal sides is isosceles, and a triangle with no equal sides is called scalene. #21 shows two equal sides so it is an isosceles triangle. #22 has three equal sides so it is an equilateral triangle. #23 has no equal sides so it is scalene. hope this helped! :)